Why open source?

One core principle of the scientific method is repeatability: the ability to continually retest and refine hypotheses. As computer software plays an increasingly large role in science, it is vital that that software be fully transparent and available to researchers: software is simply too complex to be easily reproduced from scratch by every research group. In contrast, closed source software presents a barrier to open research, because the implementation details of algorithms cannot be freely modified or even necessarily verified.

The Science Code Manifesto provides a clear and succinct list of five principles surrounding scientific software. There have also been a number of publications in recent years discussing these issues and ideas:

Further, we strive for ImageJ to be a community driven project. It is not merely an open sourceproduct, but an open source process. ImageJ follows open development practices, and provides open development tools online:

Public source code repositories including complete development history.

Using these resources, you can always observe the latest progress of the project, get an idea of where the project is heading, contribute code to the project yourself using GitHub, or write documentation, tutorials and other information on the wiki.